feat: add release-git-tag (#3)

We are adding the release-git-tag action as well as some CICD steps.

Reviewed-on: #3
Co-authored-by: Timo Behrendt <t.behrendt@t00n.de>
Co-committed-by: Timo Behrendt <t.behrendt@t00n.de>

release-git-tag/README.md

@@ -0,0 +1,9 @@
+# release-git-tag
+
+Creates and pushes a Git tag to the remote repository.
+
+```yaml
+- uses: ./release-git-tag
+  with:
+    tag: v1.0.0
+```

release-git-tag/action.yaml

@@ -0,0 +1,15 @@
+name: Release Git tag
+description: Releases a Git to origin
+
+inputs:
+  tag:
+    description: The tag to release
+    required: true
+
+runs:
+  using: "composite"
+  steps:
+    - shell: bash
+      run: |
+        git tag ${{ inputs.tag }}
+        git push origin ${{ inputs.tag }}